This invention is directed to valves for employment in the control of the flow of air from an area having high pneumatic pressure through an orifice into an area having relatively low pneumatic pressure. Such valves are frequently used in connection with the construction and rehabilitation of pneumatic pipe organs and similar devices. Such valves may also be employed in connection with pneumatic devices other than musical instruments and may find employment in any pneumatic device wherein the flow of air is valved to a chamber wherein pneumatic work is performed.
Numerous devices have been proposed for use and have been used in connection with the control of the flow of air to pipe organs. A classic work on this subject, the Art of Organ Building, George Audsley, Dover, N.Y., 1905 and 1965 describes numerous arrangements for such valves. Pages 230 et. seq. of the Audsley work discuss devices known as relief pallets which are designed to relieve the effect of pneumatic pressure upon an operative valving device to facilitate the opening of an air control orifice for the passage of air into an organ pipe. Such devices are clumsy and are not well adapted to the employment of modern means of valve actuation such as electromagnetic actuation.
U.S. Pat. Nos. 1,286,059 Morris, 1,974,530-Brown, 2,335,311 Reisner, 2,392,411 Reisner, 2,458,653 Seybold, and 2,805,595 Gundling are directed to valves for controlling the flow of air to pipe organs. U.S. Pat. Nos. 1,986,956 Brown et al and 2,089,332 Boner are directed to electromagnetic pipe organ valve assemblies which employ angular displacement of the valve with respect to the air transit orifice in an attempt to overcome pneumatic forces associated with unseating of the valve. None of the foregoing patents or publications discloses or suggests the novel, duplex valves of the present invention.